WD Backup on new MyBook 4TB - WHY SO SLOW TO CREATE BACKUP?

My new 4TV WD MyBook USB hard drive, connected to an HP desktop running Windows 7 is SLOW, SLOW, SLOW!~

For the first time backup, it has been running since about 2pm and now it is 4pm, and the dialog box shows only 4% progress, backing up only 17 GB out of 441 GB on the desktop hard drive.

WHY SO SLOW???

This is unacceptable - at this rate of 4% in four hours, it looks like it will take ONE HUNDRED HOURS to complete the backup. WHY???

Hi,

Is the computer being used? If yes, it should take to some time to avoid taking all the resources for the backup only.